I have a very early run Model 60 (no dash, early serial number delivered with high gloss finish from the factory). The yoke retention screw worked its way loose from shooting. Before tightening the screw I took the opportunity to disassemble and clean everything good. While doing so I noticed there was some wear on the yoke button where the screw contacts (see attached photograph). My question for you: is the amount of wear in the photograph fairly normal or something I should be concerned about?

The gun does get shot but not heavily and I only put light target ammo through it. Belonged to my grandfather so I want to take good care of it. First post on this forum. Thanks for helping!

You're going to get a minor burnishing of that surface when the cylinder is swung in and out. If no one ever told you, that particular sideplate screw was hand fit at the factory and is the only one that should go in that hole. It should show a slight cylinder shaped section below the threads that contact the yoke surface.

The end of the screw fits into that groove at the end of the yoke, and I don't see any wear there (and there shouldn't be if the screw is fit properly. However the sides of that groove will see some wear. This area, along with the yoke itself are the two places I use a light coating of grease on a revolver.

Assemble just the yoke and screw to the gun. Then with the yoke 1/2 way open try to push and pull the yoke. If there is no to just perceptible end shake then there is little to no wear. You can't tell a thing by looking at it!

Thanks everyone for all your helpful information! One final question on the subject: the yoke/cylinder feel stiffer than other S&W revolvers I have picked up when opening the gun if I torque the yoke retention screw down (not over-torqued, just snugged). Nothing binds up, the gun just feels stiff during open/close. Backing the torque off the yoke retention screw just a little frees things up nicely but I am concerned about the thing vibrating loose again because it has very little torque on it at this point. I see no damage to the screw or the threads in the gun’s frame. Am I doing something wrong here, or is there just a fine line between too tight/too loose that is inherent to the design?

I always put a dab of grease on the yoke at that wear point. Make sure the screw has no flaring at the tip of it that's putting undo pressure on the yoke when tightened. You should be able to tighten it like the other sideplate screws.

About the friction you feel, try the other dome headed screw in the hole and see if anything changes. If there's no change or it gets worse, the first screw might not have been properly fit. If it's better, the wrong screw was in the hole.

If you're feeling confident, you can take a Sharpie or magic marker to the yoke groove bottom and sides of the groove. Reinstall the yoke & screw and work the yoke back and forth. Remove screw and yoke and see where the contact is. I expect your screw is a wee bit long and careful filing on the tip will remove the issue.